The present invention relates generally to tire valve stem tools for installation or removal of rubber valve stems from tubeless type pneumatic tire rims. Tire valve stem tools may find use in a service garage where tires are dismounted from wheels for replacement or repair, and the valve stems are removed or replaced. Tire valve stem tools also are used to facilitate installation of a valve stem in a rim prior to mounting new tires.
Valves for tubeless pneumatic tires are typically installed in a wheel rim by pulling the valve through a mounting hole until the base of the valve is seated against the inside rim surface adjacent the valve opening of the rim. The usual method of removing the valve stem assembly for tire servicing is to pull the valve completely through the mounting hole. Some force is required both to install the valve stem and to remove the valve stem, so tools have been adapted for grasping the valve stem and for providing increased leverage for pulling.
The tools used in tire service shops include a variety of methods for attaching to or gripping the valve stem, and also include a variety of methods for providing some amount of mechanical advantage when pulling the valve stem through the opening in the rim.
One device that has been used for installing and removing valve stems from tubeless pneumatic tire rims is described in U.S. Pat. No. 1,308,219 as including a tool that connects to the valve stem with a threaded cap member adapted for screwing onto the threaded tip of the valve stem. A chain or cable has the threaded cap attached at one end with a handle attached at the other end. As originally used this tool was intended to hold the valve stem of a tire inner tube in place while the outer tire was positioned and the tube was inflated. The use of this tool for tubeless tire valve stem installation and removal was a natural evolution, but the design did not include mechanical advantage. This tool is used for valve stem installation by simply inserting the valve stem from the inside of the rim, attaching the treaded cap to the valve stem and pulling the handle until the valve is seated in the opening in the rim. The valve stem is similarly removed by simply pulling on the handle until the valve is forcibly extracted through the valve opening. As stated, this tool provides no mechanical increase in the applied force.
There are several other devices with elongated handles designed to provide mechanical advantage in the process of installing and removing valve stems from tubeless tire rims. The most common of these devices used in service garages today are described in U.S. Pat. Nos. 3,562,891 and 2,940,167. These devices provide for a means of attachment to the valve stem at one end of the handle and a method of prying the valve stem into or from the rim opening.
The devices described in U.S. Pat. Nos. 3,562,891 and 2,940,167 were preferably used on steel wheels. One problem with their use on custom wheels that may be made of steel, aluminum, chromed or other finished surface is that damage to the surface in the form of scratches or dents can be caused where the tool makes contact with the rim. It is preferable to prevent damage to the finished surface of the rim, which may be soft or highly polished.
Another problem encountered with the existing tools is that they are designed to grasp a valve stem that protrudes through the rim opening and above the surface of the rim. However, many modern rims are designed with recessed holes for the valve stem so that the valve stem does not protrude appreciably above the rim surface. These recessed valve stem holes make it difficult or impossible to either be grasped by the previous devices or to be operated on by the previous devices without causing damage to the rim surface.
One known practice for installing or removing valve stems in recessed valve openings makes use of a device similar to that described by U.S. Pat. No. 2,940,167, that consists of a threaded cap pivotally attached to an elongated handle.
One method that has been used to insert a valve stem in a recessed valve opening involves first inserting the valve stem into the valve opening from inside the rim. The threaded cap of the previously described tool is screwed onto the valve stem. A rag or other protective cushioning material is placed between the tool handle and the rim surface, and the valve stem is then pried into a seated position. Great care must be taken to avoid damage to the rim surface near the valve stem opening. For some rims, it is not even possible to apply a prying force because the rim shape blocks the movement of the handle.
To remove a valve stem from a recessed valve stem opening, one procedure is to first remove the valve core, which allows the tire to deflate, then the tire is removed from the rim, and finally the valve stem is cut from the back side of the rim to remove the valve stem from the rim. This process is more time consuming and more difficult than if the valve stem could be safely grasped with a tool for installation and removal without risk of damage to the rim.
The present invention is designed to improve upon the previous tools so that valve stems used in modern rims can be serviced easily. In one embodiment, a single-handed operation is possible without damaging the rim surface.
One embodiment of the present invention is a tire valve stem tool for tubeless tire rims that comprises an elongated handle extending between a proximal end and a distal end. The tool further includes a means for grasping a valve stem, the grasping means being attached to the distal end of the handle. The tool also includes a lever arm extending between an attached end and a fulcrum end. The attached end of the lever arm is attached to the distal end of the handle.
Another embodiment of the present invention is a tire valve stem tool that comprises an elongated handle extending between a proximal end and a distal end.
The tool further comprises a first clamping jaw member extending between a first clamping jaw attached end and a first clamping jaw grasping end. The first clamping jaw attached end is fixedly attached to the distal end of the handle and extends substantially lineally from the distal end of the handle. The tool further comprises a second clamping jaw member extending between a second clamping jaw attached end and a second clamping jaw grasping end. The second clamping jaw attached end is pivotally attached to the distal end of the handle at a pivot point substantially adjacent the first clamping jaw member. The second clamping jaw member pivots between a closed position and an open position in relation to the first clamping jaw member. The tool further comprises a lever arm fixedly attached to the second clamping jaw member and at a substantially normal angle to the second clamping jaw member. The lever arm also has a fulcrum end extending beyond the pivot point past the first clamping jaw member.
Another embodiment of the present invention is a tire valve stem tool that comprises an elongated handle extending between a proximal end and a distal end. The tool further comprises a first clamping jaw member extending between a first clamping jaw attached end and a first clamping jaw grasping end. The first clamping jaw attached end is fixedly attached and extends substantially lineally from the distal end of the handle. The tool further comprises a second clamping jaw member extending between a second clamping jaw attached end and a second clamping jaw grasping end. The second clamping jaw attached end is pivotally attached to the distal end of the handle at a pivot point substantially adjacent the first clamping jaw member. The second clamping jaw member pivots between a closed position and an open position in relation to the first clamping jaw member. The tool further comprises a lever arm extending between a lever arm attached end and a fulcrum end, wherein the length of the lever arm is between substantially one inch and substantially six inches. The lever arm attached end is fixedly attached and at a substantially normal angle to the second clamping jaw member and the lever arm fulcrum end extends beyond the pivot point past the first clamping jaw member. The fulcrum end of the lever arm has a bottom side that is in the direction of the first and second clamping jaw members. The tool further comprises a contact surface attached to the bottom side of the fulcrum end, and the contact surface is made of a polymer material.
These and other objects of the invention will be made apparent through the detailed description and through references to the drawings.